Piston



Patented Sept, 24, 1946 Kave A. Smith, Overland, Mo., assignor toLincoln Engineering Company, St. Louis, M0.,

a corporation of Missouri y vApplication October 7, 1944,SerialNo..557,587

Thisinvention relates to -pistonaand with re- Claims. (C1. 3094-4) gardto certain morespecic'features, to follower pistonsffor lubricantcontainers and the like, being an improvement over the piston shown`inthe copending U. S. patent application of k'Lutwin CpR'otter andVictor G. Klein, Serial No. 435,966, now Patent Number 2,394,488, ledMay 7, 1943. for Lubricating apparatus.

Among the several objects of the invention may benoted "the provision ofa piston which great- 1y simplifies assembling Yprocedure and reducesthe cost of manufacture; and the provision of a piston Lof the classdescribed which veliminates several unhandy fasteners,whereby'replacement in the eld of its packing member may readily beaccomplished entirely without tools. Other objects will be in partobvious and in 'part pointed out hereinafter.

The invention `accordingly comprises the -elements and combinations ofelements, features of construction, and arrangements of parts which willbe exemplied in the structureshereinafter described, and the scope ofthe application of which will be indicated in the following claims.

In `the accompanying drawing, in lwhichis illustrated one of variouspossible embodiments of the invention,

Fig. 1 is a plan view of one side of..my new piston;

Fig. 2 is a plany viewof the opposite side of the'piston;

Fig. 3 is a View similar to Fig. l showing a preliminary assembly .ordisassembly operation;

Fig. 4 is a vertical section taken on line 4-4 of Fig. 1 but showingalso the cylindric lubricant compartment of a lubricant pump, for whichthe piston is adapted; and

Fig. 5 is an explodedv view of the shown partially disassembled.

Similar reference characters indicate corresponding parts throughout theseveral views of the drawing. Y

Referring now more particularly to Figs. 1, 2 and 4, numeral indicatesmy new piston assembled for insertion into a cylinder, the latter beingshown at numeral 3 in Fig. 4. This piston is intended to actk as alubricant follower, on lubricant carried beneath and in the cylinder 3.To

piston parts this end it Aslides upon a retractor rod 5 and is biased bymeans of a spring I. Sometimes followers of this type are used'incylinders without rods such as 5.

The invention has to do with the piston per se. 'Ihis consists of anlintermediate resilient packing diaphragm 9, consisting preferably ofsynthetic rubber or the like which is chemically resistant to attack bylubricants, such as for example, neoprene This packing has an elongatehub part II which hugs the retractor rod 5. On its periphery areopposite edgewise lips |3wl1ich hug the inside 'of the cylinder 3. 'Onemetal'head lof the piston is shown at i5 andanother at Il. Each head I5andv I1 carries a sliding hub I9. The `hubs are oppositely directed to'accommodate the resilienthub I I of the pack-V ing. Each head I5 and Ilis also provided with `an edgewise beveled portion 2| Vfor accommodatingthe lips I3, these beveled portions beingalso oppositely directed.

The head I5 is Nprovided with preferably diametrically opposite holes23v for accommodating the straight shanks 25 of a pairof holding studs.The shanks pass through said `'openings 23 and also through alignedopenings `2l' in the-packing El.v The openings 21 are ofa size adaptedto grip and seal around the shanks 25.

Each shank, beyond the diaphragm 9, is grooved, as shown at 29. What maybe called a head kportion 3| is preferably of the same diameter as shank21. The grooves 29 are arrangedin a plane next to one face of thepacking 9, said planer being the one which the head |1 isto assume.

As indicated in Figs. 1 and 3., the head l1 is provided with keyholeopenings 33. The small endsor notches 35 of `these openings arepreferably opposite and must be centered with the openings 23 in theopposite head I5. The enlarged portions 3l of the openings 33 areopposite but not diametrically opposite. Thus the directions of thekeyholes are opposite since the left-hand keyhole in Fig. 3 pointscounterclockwise and the right-hand hole 33 Vpoints clockwise. Eachenlarged end 31 of each hole 33 freely-accommodates a head 3|; whereasthe small notched part 35 accommodates only the grooved portion 29.

Assembly or disassembly is quite easily carried out as is airmedbyfcomparing Fig. 3 and Fig. 1. In Fig. 3 the studs 25 have beeninserted through the'openlngs in the head I5 (see also the lefthand partof Fig. 5). Next, the packing-is assembled'by inserting the studs 25through the openings 2l Vin the packing. Then as shown in Fig. 3, thelarge portions 3l of the keyhole openings 33 are applied axially overthe heads 3|. Then the head |1 is slipped laterally into the positionshown in Fig. 1, wherein the small ends 35 of the notches 33 are keyedinto the recesses 29.

The piston thus assembled may be applied to rod 5 and inserted intothe'cylinder 3 and thereafter the head cannot slip back into the Fig. 3position because the rod 5 prevents any substantial misalignment betweenthe head I1 and the packing 9 to the extent that would be required fordisassembly. It will be noted that one reason for this fact is that thekeyhole openings 33 are not pointed in the same direction around theclock. If they were, the head I1 could, even in the cylinder 3, twistaround to a disassembling position. Y e

3 It will be noted that for disassembly purposes the lengths of thesmall portions 35 of the keyhole slots 33 are enough to require a degreeof misalignment between the head .l1 and the packing 9 which is greaterthan the misalignment which will be permitted by the rod or the cylinj 1der 3 in which the piston I operates.

To disassemble the piston is quite easy for all that needs to be done isto remove it from cylinder 3 and rod 5 and then move the head l'l `fromthe position shown in Fig. 1 to that shown in Fig. 3; After this it maybe removed axially as suggested in Fig. 5. Removal of the packingdiaphragm from the unthreaded studs 25 is then quiteeasy and may beIaccomplished without damage.

From the above it will be seen that the invention avoids all threadedstuds, nuts, washers and the like, and that assembly and disassembly mayreadily be accomplished entirely by hand, without tools. It alsosimplies assembly and disassembly and reduces the cost of manufacture.It will be noted that a part of the reason for the simplificationaccomplished is the use of the rod 5 (on which the piston operates) forpreventing working loose of the head l'i. In other words, the head I1needs to pass through a sequence of positions for disassembly which therod 5 will not permit when the piston is thereon. It Will be understoodthat in cases where the follower is used in a cylinder without a rodsuch as 5, the heads I5 and I1 are made without central openings andthat in such cases it is the cylinder such as 3 which prevents the headI1 from passing through a sequence of positions which would cause itsdisassembly in the cylinder. Broadly considered, either cylinder 3and/or rod 5 may be considered to be a cooperating cylindric member inconnection with which the piston operates, whereby is preventeddisassembly under Working conditions.

While a single keyhole slot andY one stud could be used, two or morewith a symmetrical relationship between the stud positions is preferablefor a balanced holding action by the studs.

In View of the above, it will be seen that the several objects of theinvention are achieved and other advantageous results attained. I

As many changes could be made in the above constructions withoutdeparting from the scope of the invention, it is intended that allmatter contained in the above description or shown in the accompanyingdrawing shall be interpreted as illustrative and not in a limitingsense.

I claim: i

1. A piston comprising an intermediate packing member, a head on oneside of said member having openings, said packing having ropeningsaligned therewith, studs passing through said openings, a second head onthe opposite side of said packing member, said studs having recesses inthe plane of said second head and adjacent to the packing, and keyholeopenings in the second head having notched portions cooperating onlywith said recesses respectively and being oppositely directed withrespect to the clock, said keyhole openings having enlarged portionsaccommodating the non-grooved portions of said studs beyond the grooves,said heads and packing being adapted to be maintained in alignment bythe interior wall ofl the cylinder in which said piston is used.

2. A piston comprising an intermediate packing member, a head on oneside of said member having diametrically opposite openings, said packinghaving openings aligned therewith, studs portions cooperating only withsaid grooves and y, oppositely directed with respect to the clock, saidnotched portions being diametrically opposite one another, said keyholeopenings having enlarged vportions accommodating the non-groovedportions of said studs beyond the grooves, said heads and packing beingadapted to be maintained in alignment by the interior wall of thecylinder in which said piston is used.

3. A piston comprising an intermediate packing member, a head on oneside of said member having diametrically opposite openings, `saidpacking having openings aligned therewith, studs vpassing through saidopenings, a second head on the opposite side of said packing member,said studs having grooves in the plane of saidv second head adjacent tothe packing, and keyhole openings in the second head having notchedportions cooperating with said grooves and oppositely directed withrespect to a radius of the piston, said keyhole openings having enlargedportions accommodating the non-grooved portions of said studs beyond thegrooves, the length of said notched portions of the keyhole openingsbeing such as to require for disassembly a misalignment between the headin which they are located and the packing member which is greater thanthat which ris permitted by the cylindric member in connection withwhich the piston cooperates.

4. A piston comprising an intermediate packing member, a head on oneside of said member having an opening, said packing having an openingaligned therewith, a stud passing through said opening, a second head onthe opposite side of said `packing member, said stud having a groove inthe plane of said second head adjacent to the packing, and a keyholeopening in the second head having a notched portion cooperating onlywith said groove, said keyhole opening having an enlarged portionaccommodatingthe groove of said stud, the length of said notched portionof the keyhole opening being such as to require for disassemblya-misalignment between the head in which it is located and the packingmember which is greater than that which is permitted by the cylindricmember in connection withwhich the piston cooperates.

,5. A piston comprising an intermediate packing member and a pair ofheads between which the packing member is disposed, a post projectingfrom one head through an ope-ning in said packing member, and through akeyhole opening in the other head, said keyhole opening being formed toprovide an aperture larger than saidpost and a smaller notched portionextending therefrom, said post having a groove in the plane of saidother head adjacent the packing member, said notched portion cooperatingwith said groove to prevent axial lseparation ofV the heads and packingmember and being ofv such length and extending from said aperture insuch direction as to prevent both relative rotation and separation ofsaid other head when the heads and packing member are maintained inalign-

